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Bottom line is the "All Electric" bar above..in all cases, is less wheel-to-wheel polluting than any other type of car.
"Direct and Well-to-Wheel Emissions
Vehicle emissions can be divided into two general categories: air
pollutants, which contribute to smog, haze, and health problems; and
greenhouse gases (GHGs), such as carbon dioxide and methane. Both
categories of emissions can be evaluated on a direct basis and a
well-to-wheel basis.
Conventional vehicles with an
internal combustion engine (ICE) produce direct emissions through the
tailpipe, as well as through evaporation from the vehicle's fuel system
and during the fueling process. Conversely, EVs produce zero direct
emissions. PHEVs produce zero tailpipe emissions when they are in
all-electric mode, but they can produce evaporative emissions. When
using the ICE, PHEVs also produce tailpipe emissions. However, their
direct emissions are typically lower than those of comparable
conventional vehicles.
Well-to-wheel emissions include all emissions related to fuel
production, processing, distribution, and use. In the case of gasoline,
emissions are produced while extracting petroleum from the earth,
refining it, distributing the fuel to stations, and burning it in
vehicles. In the case of electricity, most electric power plants
produce emissions, and there are additional emissions associated with
the extraction, processing, and distribution of the primary energy
sources they use for electricity production."